Spring-powered key action



J. P. WESLEY SPRING-POWERED 'KEY ACTION July 22, 1947.

Filed Aug. 28, 1946 2 sheets-sheet 1 MN: .n

Inventor By QM July 22, 1947. J. P. WESLEY SPRING-POWERED KEY ACTIONFiled Aug. 28, 4194e; 2 sheets-sheet 2 I :mentar Patented July 22, 1947'UNITED STATES ATENT OFFICE SPRING-POWERED KEY ACTION .I ames P. Wesley,Glendale, Calif.

Application August 28, 1946, Serial No. 693,483`

3 Claims. l

This invention relates to key actions for typewritng and otherkey-operated machines.

In the key actions of typewriting machines, it is conventional practiceto so connect the key lever vwith the type bar that the latter, afterbeing moved to printing position, may return to normal positionindependently of the key lever, to permit operation of another key leverwithout waiting for the previously operated key lever to return tonormal position. This has been accomplished by providing a releasableconnection between the key lever and the type bar, and means to releasesaid releasable connection between the key lever and the type bar afterthe latter has been given sulcient momentum to effect the printing andjust before movement of the key lever has been completed. In prioractions, however, the type bar is moved toward printing position by thekey lever and the momentum of the type bar and the force with which theprinting character thereof strikes the printing ribbon depends upon theforce of the impact of the finger with the key lever. As a result ofthis, operation of the typewriter causes considerable fatigue on thepart of the operator and the printed characters vary as to tone.

The primary object of the present invention, therefore, is to provide animproved typewriter action by means of which the above objections ofprior actions are overcome.

In carrying out the present invention in connection with a typewriter, Iprovide a power unit for moving the type bar to printing position, meanswhereby the potential energy of said unit is increased as the key leveris depressed, and

means to automatically disconnect the key lever and type bar when thepotential energy of the power unit israised to a predetermined degreeand before depression of the key lever has been completed. When thepower unit actuates the type bar, the increased energy thereof is spent,so that relatively weak springs may return the key lever and type bar totheir normal positions and reset the detachable connection between thesame for the next operation of the action. Thus, the operation of thepresent action does not depend upon the force of impact of the nger withthe key lever. Instead, the operation depends only upon the distance ofmovement of the key lever, and the momentum of the type bar in moving toprinting position is always the same and is caused by the power unitinstead of by variable manual force applied by the operator to the keylever. Consequently, operation of the present action causes less fatigueof the operator, and the Csi characters are always printed in the Vsametone so that the printed page is clear and easy to read and has auniform and sightly appearance. Also, care on the part of the operatoris unnecessary, and greater typewriting speed is made possible.

A further object of the invention is to provide a key action for keyoperated machines, which is highly efficient in operation, comparativelysimple in construction, and otherwise well adapted to meet therequirements for successful commercial use.

The exact nature of the present invention, as well as other objects andfeatures thereof, lwill become apparent from the following descriptionwhen considered in connection with the accompanying drawing, in which.:

Figure 1 is a cross sectional View of a typewriting machine having oneform of key action embodying the present invention;

Figure 2 is a fragmentary plan view showing the parts of a single keyaction of the form embodied in the machine of Figure 1;

Figure 3 is a perspective View of the construction shown in Figure 2;

Figure 4 is an enlarged fragmentary vertical section through the partsof the action, taken on line 4 6! of Figure l;

Figure 5 is a view similar to Figure 4, showing the key lever depressed;

Figure 6 is a fragmentary transverse section takenon line 64-6 of Figure1.

Referring in detail to the drawing, wherein one embodiment of theinvention is merely illustrated by way of example, 5 indicates the frameof a typewriting machine, and 6 the platen thereof. A wide bar orplate'l extends across the machine and carries the pivots for the type b-ars,one of which is shown at 9. A key lever l0 is pivoted upon the pivot pin8 of each type bar 9, and each key lever is returned to its normalelevated position by spring Il. Also, each type bar 9 is swung away fromthe platen f5 to a normal inoperative position by means of a spring l2.

In accordance with the illustrated embodiment of the invention, each keylever is provided between its endswith a laterally projecting cam lug l3 beneath which is normally engaged a latch element I4 carried by alaterally iiexible leaf spring l5 which is attached to a forwardlyprojecting short arm IB provided on the pivoted end of the associatedtype bar 9. Also, the arm I6 is provided at its free forward end with alateral lug l1 which bears upon a leaf spring I8 forming part of a powerunit mounted upon the bar or plate l. This power unit also includes ablock I9 fixed upon the bar or plate I and having one end of the springI8 xed thereon. Fixed upon the bar or plate 'I beneath the latch elementI4 is a cam plate 20, and the arrangement is such that the latch elementI4 is normally engaged beneath the cam I3 of key lever I0 for beingdepressed by the latter. Thus, as the key lever I is depressed, the typebar 9 is swung slightly further away from the platen B and arm |16 iscaused to lower for increasing the potential energy of the power unitI8, I9. As the key lever I9 moves downwardly, the cam 20 causes lateralmovement of latch element I4 as allowed by spring I5, until 1 key III iscompleted, and it results in freeing the Y type bar -9 from theassociated key lever I0 so that the energy of the unit I8, I9 isreleased so that said unit instantaneously swings the type bar 9upwardly and rearwardly into printing position as shown by dotted linesin Figure 1. When this occurs, the increased energy of the power unit isspent so that upon removal of the finger from the actuated key lever I0,the springs II and I2 will return the key lever I0 and type bar 9 totheir normal positions as shown in Figure 1. When the parts 9 and I0thus return to their normal positions under the inuence of the springsII and I2, the latch element I4 passes downwardly along the inclinededge of cam I3 until said latch element is located completely below saidcam I3, whereupon the spring I5 moves the latch element I4 laterallytoward the key lever IIJ and engages it beneath the cam I3. In this way,the latch element I4 is reset in latching position so that the action isconditioned for the next operation thereof.

It will of course be understood that the strength of spring I2 issuicient to overcome the action of spring I8 and the resistance offeredby spring I5 in causing passage of the latch element I4 past and belowthe cam i3, in the resetting operation. On the other hand, when the keylever I0 is depressed, the energy of spring I8 is increased to a pointabove the strength of spring I2 so that such increased energy of springIH will be sufficient to move the type bar 9 to printing positionagainst the action of spring I2.

From the foregoing description, it is believed that the construction,operation and advantages of the present invention will be readilyunderstood and appreciated by those skilled in the art. While I haveillustrated, merely by way of example, one specific embodiment of thepresent invention, it will be understood that many widely differentmodifications of the invention are possible. Accordingly, the inventionbroadly contemplates any mechanism in which energy supplied by thefinger in depressing the key is used to raise the potential energy ofsome power unit; in which a releasing mechanism then frees the potentialenergy of this unit. and the energy thus released then drives theactuated part or type bar so as to cause the latter to be actuated ormoved to printing position; and in which some device is used so that thekey and actuated part or type bar'are returned to their originalpositions and the mechanism is reset when the finger is removed from thekey. The important facts are that the mechanism is such that theoperation of the action does not depend upon the force of impact of thefinger with the key lever, but depends only upon the distance ofmovement of the key lever. Also, the momentum of the type bar in movingto printing position is always the same and is caused by the power unitinstead of the variable manual force applied by an operator to a keylever. It will accordingly be apparent that the present action willcause less fatigue of the operator, and that the characters will alwaysbe .printed in the same tone without any exercise of care on the part ofthe operator and so that greater typewriting speed is made possible.

Having now fully described my invention, what I claim as new is:

1. In a typewriting machine, the combination of a lkey lever having alateral keeper cam, a type bar having an arm provided with a laterallug, a spring attached to said arm and carrying a latch engageablebeneath the keeper cam to connect the key lever and type bar, a powerunit including a spring depressable by the lug of said arm upondepression of the key lever to have the potential energy thereofincreased, and a cam arranged in the path of said latch to disengage itfrom beneath the keeper cam and thereby disconnect the type bar and keylever before movement of the key lever is completed, whereby theincreased energy of the power unit spring is utilized to swing the typebar to printing position.

2. The construction dened in claim 1, in combination with springs forreturning the key lever and type bar to their normal positions and toreset the latch beneath the keeper cam when the increased energy of thepower unit spring is spent and the finger is removed from the key lever.

3. In a typewriting machine, the combination of a key lever having alateral keeper cam, a type bar having an arm, a spring attached to saidarm and carrying a latch engageable beneath the keeper cam to connectthe key lever and type bar, a power unit including a spring coactingwith said type bar so as to have its potential energy increased upondepression of the key lever, and a cam arranged in the path of saidlatch to laterally move and disengage it from beneath the keeper cam andthereby disconnect the type bar and key lever before movement of the keylever is completed, whereby the increased energy of the power unitspring is utilized to swing the type bar toprinting position.

JAL/LES P. WESLEY.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 886,447 Wahl May 5, 1908 970,250Mailman Sept. 13, 1910 1,667,773 Degener May 1, 1928 2,206,624 Bates etal July 2, 1940

